Railway signaling apparatus



R. M. GILSON K RAILWAY SIGNALING APPARATUS Filed Sept. 3. 1924 March 24,1925. 1,530,663

M. ATTo'RNEY BY I "ventionl Patented Mar. 24,1925..

i UNITE-D g sra-rss varietur oFFIcE.

ROBERT M. G'Irsoir, or PI'TTsBURIGR, rnniisrnvanrm ass'IenoR To THRUnion swrciir s ,s'IGNAL'coMPANm or swssvann, rRNNsYLvaRiA, ACORPORATION or PENNSYLVAR'IA.,

RAILWAY sieNALrne APPARATUS.

Apnc'anon mea september 3, 1924. s'riain'o. 735,717.

ToV all whom t may concern."

Be it known that L ROBERT M. GiLsoN, a citizen of the United States,Vresiding at Pittsburgh, in the county'of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements in Railway bignaling Apparatus, of which the following is a specification.

My invention relates to railway signaling, and particularly to signalingof the type comprising track circuits.

@ne feature of my invention is the provision in signaling of this typeof means for preventing a false clear indication in the event ofmomentary failure of a car or train to effectively shunt a track relay.4

I will describe two forms of signaling apparatus embodying my invention,and will then point out the novel features thereof" in claims.

In the accompanyingdrawing, Fig. 1 is a diagrammatic view showing oneform of signaling apparatus embodying my in- Fig. 2 is a diagrammaticview showing a modification of the apparatus shown in' Fig. 1 and alsoembodying my f invention. Fig. 3 is a` view partly diagram` matic,showing one form of relay which may be used with the signaling apparatusshown in Figs. 1 and 2.

Similar reference characters refer to similar vparts in each of theseveral views. v

Referring first to Fig. 1, the reference characters 1 and 1a designatethe vtrack rails of a railway along which traiic normally moves inI thedirection indicated by the arrow. These rails are divided by insulatedjoints 2 to form a track section A-B Located adjacent theexit end of thesection A-B is a track transformer` T, the

secondary 3 of Vwhich is connected across thc rails of the section. Theprimary l of this transformer is connected'with a transmission line Lwhich is constantly supplied with alternating signaling current by agen,- erator D. j

Located adjacent the entrance end of the section A-B is a track relayC.' This're'lay C is connected with the track rail's'through a stick orholding circuit, which circuit passes fromthe lower track rail 1a,through wires 5 and 6, front cont-act 7 of'relaygC wires 8 andl 9,winding of relay C, wire 10,

to the upper track Vrail 1. Relay C is provided with a-vpick-up circuitwhich passes fromv the lower track rail 1a, through wires 5 andv '11,back contact 12 of an auxiliary relay D, Uwires13 and 9, winding ofrelay C, and w'ire 10 to the upper track rail 1. lt will be seen,therefore, that the back .con-V tact 12 of'relay 'D is in abranch-around front contact 7 of relay @,jand it will also be seen thatwhen `relay Gis cle-energized it can become energized only when backcontact 12 of relay D is closed.

Relay D is provided with a circuit which passes froml secondary 17' of atransformer U, through -wire 3L, front point of contact 3'2-32a of trackrelay C, winding of relay D, andk wireg33 tov secondary 17.0ftransformer U.- Relay D is energized, therefore, when track relay C isenergized, but is deenergized when track .relay C becomes deenergiz'ed.The primary 13 `of, transformer U is connected with the transmissionlineL. W Located adjacent the entrance end of track section A-B is asignalS, which,.as here shown, is a light signal comprising two lamps Grandk R, adapted when lighted to indicate .proceedWand stop,respectively.

The proceedlamp G is provided with a cirpasses from the secondary 17,through wireV `V 31, back contact 352-32b oftrack relay C, stop lamp R,4andwire 33 to secondary 17. The stop lamp R is also provided with a.circuit which passes from secondary 17.

through wire31, back contact 28-30 of auxiliary relayD, lamp R, and wire33 to secondary 17. It will be seen, therefore, that signal S' willindicate proceed only when the front contacts of both relays C and D areclosed, and will indicate stop when the back contacts ofici'ther relay Cor D are closed." n

The auxiliary relayfD-is so constructed as to consume a considerableinterval of time between the opening of its back con tactsf and therclosing offit's front contacts when the relay becomes energized.Referring to Fig.` 3, this relay in the form here shown comprises arotor 2O operated by a winding 21. The rotor operates apinion 22 meshingwith a segmental gear 23 pivoted at 23a and biased by gravity to engagewith. a fixed stop 26. When the winding 21 is cle-energized,thersegmental gear 23 occupies the position in which it is shown in thedrawing, wherein back contacts 28-30 and 12 are closed rdue to theaction of a knob 25. When winding 21 becomes energized, the pinion 22will swing the segmental gear 23 upwardly until it engages with a xedstop 27. As soon as this upward movement of the` segmental gear begins,the lower knob 25 will allow the back contacts 28-30 and 12 to open, andjust before the segmental gear engages the upper fixed stop 27, theupper knob 24 will cause the front contact 28-29 to close. Obviously, aconsiderable interval 'of time elapses between the opening of the backvcontacts and the closing of the front contact, and this interval may bekmade any desired value.

Referring again to Fig; 1, when the track section ltr-B is unoccupied,track relay C is energizedand auxiliary relay D is energized, so thatsignall S indicates proceed. When a car enters track section A-B it willcle-energize the track relay C, thereby opening the circuit for theproceed lamp G at front contact 34 and closing the circuit for the stoplamp R at back contact 252-32?, so that signal S will then indicatestop. Relay VD also becomes cle-energized and after the interval of timerequired for segmental gear 23 to reach its lowest position, the backcontacts of this relay will become closed. When the car leaves the tracksection 5L-B, track relay C will become energized through its pick-upcircuit which includes back contact 12 of relay D, and will then remainenergized due to its stick or holding circuit which includes contact 7ofv relay C. After the interval of time required y for the operation ofrelay'D, front Contact (lil 28-29 of this relay will becomel closed,whereupon signal S lwill change from the stop to the proceed indication.

l will now assume that the track rails of section A-@B are covered bysand or Lrust throughout a stretch indicated by the line 35 in Fig. 1,and that this stretch-'is of such length that the time consumed by a cartraveling at normal speed and lpassing over this stretch is less thanthe time required forthe front contact of auxiliary relay D to closeafter the relaygbecomes energized. When the car enters the stretch 35,track relay C will become energized due to the fact that its pick-up'circuit is closed at back contact 12 of relay D,` and the closing offront contact 32--32a of track relay C will close the circuit for relayD'. Before the front contact 28-29 of relay D becomes closed, however,the car leaves the stretch 315 and againV shunts -relay C, which relaytherefore becomes de-energized and. again opens the circuit for relay Dat contact 32--32a- During the time that the car was on the stretch 35,front contact 28-29 of relay D did not become closed, and, consequently,the proceed ,lamp 'G of signal S didA not become lighted. It followsthat the picking up of track relay C due to the sanded or rusty stretch35 willnot cause signal S to give a false indication.

lv will now assume that. the section A B contains a stretch36 in whichVthe rails are covered with sand or rust, which stretch 36 is longer thanstretch 35 and is of such length that the time consumed by' a carpassing thereover is greater than the time required for the frontcontact of auxiliary relay D to closey after this relay becomesenergized. l will furthermore assume, however, that the stretch 36contains a short gap 37 in which the rails are clean so that relay Cwill be shunted while the car is passing over this gap. The sanded orrusty stretch on each side of the gap 37 is of such Vlength that thetime consumed by a car traveling thereover at normal speed is less thanthe time required for. the front contact of relay D to close after thisrelay becomes energized. When. the car enters the stretch 36, trackrelay C will become energizech-and so the closing operation of auxiliaryrelay D will begin. Thisclosing operation will not be completed when thecar reaches gap 37. lVhenthecar strikes the gap 37 track relay C willbecome k(le-energized because back contact 12 of relay D -is' then open.This cle-energization of relay C willde-energize relay D, whereuponrelay C will not become energized until back contact 12 of' loo relay Dcloses.- This will, ofcourse, occur at some point in the stretch 36beyond lthe gap 37, and when such point is reached the cycle ofoperat-ions of relays C and D will begin again; that is',`relay C willbecome energized, thereby energizing relayD, but the latter relay willnot have time to close its front contact 28'-29 before thecar passes offof the stretch 36. When the car leaves the stretch 36, track relay Cwill become de-energized, andwill remain cle-energized until the carleaves track section A-PL It follows that while the car is Apassing overthe sanded orrusty stretch 36,'signal S will not. give a falselindication because at no time are front contact 28-29 and front Vcontact34- closed simultaneously.

vReferring now to Fig. 2, the signaling apparatus shown in this view isthe same as that shown in Fig. 1, except that the trackway signal, whichis designated S in Fig. 2, is of the three-indication type, comprisingthree lampsG, Y and R, arranged when lighted to indicate proceed,caution and lliU Y tion-type, comprising a track winding le and a localwinding l5 constantly energized by the secondary 1'? of transformer U.fr pole-changer I) is interposed between the transmission line andthetransformer T for reversing the relative polarity of the cur-y rentsupplied to the track rails by this transf former. This pole-changer maybe operated by suitable means, not shown in the drawing. The trackwinding 14 of track relay C is controlled in the same manner as thewinding lll of track relay C in Fi il.,

`When pole-changer P is Vin one position and section 15x-B isunoccupied, relay C is energized in such direction that contact lll- 34ais closed, so `that the proceed lamp (l of signal Si is lighted. Whenpolechanger l is reversed track relay C becomes energized in the reversedirection, whereupon contact 25a-34" becomes closed and the caution lampY is lighted. lWhen section fik-Ii is occupied, track relay C is(le-energized, so that auxiliary relay -D is cle-energized, and the stoplamp It of signal S isV then lighted through back contact .9S-B0 ofrelay I). It will be noted that relay D is energized whenever trackrelay C is energized in either direction, that is, whenever eithercontact 3232a or SEZ- 32 is closed. It will also be noted that theholding or stick circuit for track relay C is closed whenever this relayis energized in either direction, that is, whenever con.- tact 7-7a orcont-act 7 7? is closed. Back contact 12 of relay I) is connected in abranch around either contact 7-7 or 7 7" of relay C.

The operation of the signaling apparatus shown in Fig. 2, in so far assanded or rusty stretches of track are concerned, is the same as theoperation of the apparatus shown in Fig. l. i

Signaling apparatus embodying my invention is particularly well adaptedfor use where it is impossible to maintain a cont-inuous shunt on thetrack relay, such, for example,fas on railways using lightweight cars ormotor busses and subject to stretches of rusty orsanded rails, etc.

Although I have herein shown and described only two forms of signalingapparatus embodying my invention, it is understood that various changesand modifications inay be made therein within the scope of the appendedclaims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim isz l. In combination,a track circuit including a track relay connected with the rails througha front contact thereof, a branch around said front contact including aback contact of a slow-acting relay, a circuit for said slow-actingrelay controlled by alfront contact of said track relay, and signalingapparatus controlled by said slow-acting relay. i Y u 2. In combination,a track circuit including a track relay connected with the rails througha front Contact` thereof, a branch around said front contact includn inga back contact of a slow-acting relay, a circuit for said slow-actingrelay controlled by a front 4contact of said track relay, and signalingapparatus controlled jointly by saidtrack relay and said slovsT-V actingrelay.

In combination, a Vsection of yrailway track, a first relay providedwith a holding circuit including a front contact thereof, means`responsive to the. presence of a train in said section. fortie-energizing said first relay, a lpick-up circuit for said first relayincluding a back contact of a slowacting relay, a circuit for saidslow-acting including a back contact of a slow-acting relay, a circuitfor said slow-acting relay controlled by a front contact of said firstrelay, and signaling apparatus controlled jointly by said first relayand said slowacting relay. Y

5. In combination, a track circuit including a track relay connectedwith the rails through a front contact thereof, an auxiliary Vrelayhaving a front and a back contact and constructed to consume aconsiderable interval of time between the opening of the back contactand the closing of the front contact when theprelay becomes energized, abranch around said track relay frontcontact including the back contactof said auxiliaryy relay, a circuit for said auxiliary relay controlledby a front contact of saidl track relay, and signaling apparatuscontrolled by the front contact of said auxiliary relay. Y y

6. In combination, a track circuit including a track relay connectedwith the rails through a front contact thereof, an auxiliary relayhaving a front and a back contact and constructed to consume aconsiderable interval of time between the opening of the back Contactand the closing of the front contact when the relay becomesenergized, abranch around said track relay front contact including the back contactof said auxiliary relay, a circuit for said auxiliary relay controlledby a front contact of said track relay, and

signaling apparatus controlled jointly by said track relay and the frontContact 'of said auxiliary relay.

` 7. ln combination, a section or' railway track, a rst relay providedWith a liolding circuit including a front Contact thereof, ineansresponsive to the presence of a train in said section for cle-energizingsaid first relay, an auxiliary relayk having a front and a back `Contactand constructed to consume a Considerable interval of time between theopening of the back Contact and the closing o?? lalle 'front Contactwhen the relay beeoines energized, a pick-up eireuit for said firstrelay including the back ContactA of said auxiliary relay, a circuit forsaid auxiliary relay controlled by a front contaet of said first relay,and signaling apparatus controlled by the front con-v tact of saidauxiliary relay. v

8. In combination, a section oi" railway tween the opening` of the backContact and the closingl of the front Contact when the relay becomesenergized, a piek-up circuit for said lirst relay including the backcontact of said auxiliary relay, a `circuit for said auxiliary relayControlled by a front Contact of said irst relay, and signalingapparatus controlled jointly. by said first relay and the front Contactof said auxiliary relay. 1

In testimony whereof l affix my signature.

ROBERT M. sensori.V

